Systems and methods for mixing exhaust gases and reductant in an aftertreatment system

ABSTRACT

A vane swirl mixer for exhaust aftertreatment includes: a vane swirl mixer inlet; a vane swirl mixer outlet; a first flow device including: a Venturi body; a plurality of upstream vanes positioned within the Venturi body; a plurality of upstream vane apertures interspaced between the plurality of upstream vanes; a plurality of downstream vanes positioned within the Venturi body; and a plurality of downstream vane apertures interspaced between the plurality of downstream vanes. At least one of the upstream vane hub and the downstream vane hub is radially offset from a Venturi center axis, thereby causing individual ones of the plurality of vanes coupled to the radially offset vane hub to differ in their geometry.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 16/442,014, filed Jun. 14, 2019, the contents of which areincorporated herein by reference in their entirety.

TECHNICAL FIELD

The present application relates generally to the field of aftertreatmentsystems for internal combustion engines, and more particularly to a vaneswirl mixer used in such aftertreatment systems.

BACKGROUND

For internal combustion engines, such as diesel engines, nitrogen oxide(NOx) compounds may be emitted in the exhaust. To reduce NOx emissions,a selective catalytic reduction (SCR) process may be implemented toconvert the NOx compounds into more neutral compounds, such as diatomicnitrogen or water, with the aid of a catalyst and a reductant. Thecatalyst may be included in a catalyst chamber of an exhaust system,such as that of a vehicle or power generation unit. A reductant, such asanhydrous ammonia, aqueous ammonia, diesel exhaust fluid (DEF), oraqueous urea, is typically introduced into the exhaust gas flow prior tothe catalyst chamber. To introduce the reductant into the exhaust gasflow for the SCR process, an SCR system may dose or otherwise introducethe reductant through a dosing module that vaporizes or sprays thereductant into an exhaust pipe of the exhaust system up-stream of thecatalyst chamber. The SCR system may include one or more sensors tomonitor conditions within the exhaust system.

Once the reductant is introduced into the exhaust gas flow, the two needto be mixed. WO 2018/226626 A1 discloses a multi-stage mixer which isconfigured to receive exhaust gas and reductant and mix the reductantwith the exhaust gas to provide the exhaust gas mixed with reductant toa catalyst. The application recognizes that it is beneficial to providethe catalyst with a substantially uniform flow of exhaust gases andreductant, facilitate substantially uniform reductant distribution inthe exhaust gases downstream the multi-stage mixer and provide arelatively low pressure drop in a relatively compact space compared toconventional aftertreatment systems. The known multi-stage mixer uses aVenturi to introduce a swirl mix into the exhaust flow and uses a radialoffset of that Venturi from the center axis of the multi-stage mixer soas to cause any reductant build up on the Venturi body to besubstantially redistributed to the exhaust gases downstream of themulti-stage mixer.

However, the known multi-stage mixer, while a significant improvementover the prior art, is not proportionally scalable over the completerange of diesel engine systems due to restrictions on space claim. Thus,so as to allow better scaling while still causing any reductant build upon the Venturi body to be substantially redistributed to the exhaustgases downstream of the mixer, an improved mixer would be desirable.

SUMMARY

In an embodiment a vane swirl mixer for exhaust aftertreatment iscentered on a mixer center axis and comprises a vane swirl mixer inlet,a vane swirl mixer outlet, a first flow device and a Venturi body. Thevane swirl mixer inlet is configured to receive exhaust gas. The vaneswirl mixer outlet is configured to provide the exhaust gas to acatalyst. The first flow device is configured to receive the exhaust gasfrom the vane swirl mixer inlet and to receive a reductant such that thereductant is mixed with the exhaust gas within the first flow device.The first flow device includes a Venturi body defined by a body inlet influid communication with the vane swirl mixer inlet and a body outlet influid communication with the vane swirl mixer outlet. The Venturi bodycomprises a Venturi center axis. A plurality of upstream vanes ispositioned within the Venturi body and proximate the body inlet, whereineach of the upstream vanes is coupled to an upstream vane hub. Aplurality of upstream vane apertures is interspaced between theplurality of upstream vanes. The plurality of upstream vane apertures isconfigured to receive the exhaust gas and to cooperate with theplurality of upstream vanes to provide the exhaust gas with a swirl flowthat facilitates mixing of the reductant and the exhaust gas. Aplurality of downstream vanes is positioned within the Venturi body andproximate the body outlet, wherein each of the downstream vanes iscoupled to a downstream vane hub. The plurality of downstream vaneapertures is interspaced between the plurality of downstream vanes andthe plurality of downstream vane apertures is configured to receive theexhaust gas and cooperate with the plurality of downstream vanes tofacilitate mixing of the reductant and the exhaust gas.

At least one of the upstream vane hub and the downstream vane hub isradially offset from the Venturi center axis, causing individual ones ofthe plurality of upstream vanes to differ in their geometry and/orindividual ones of the plurality of downstream vanes to differ in theirgeometry, as the case may be.

In this embodiment, the offset of the mixer vanes and thereby thevariably geometry effectively redistributes the reductant within theswirl flow. At the same time the other components can be centered on themain axis of the vane swirl mixer allowing for concentric parts that areeasier to scale and manufacture for various sizes of engines and exhaustsystems.

The downstream vane hub may not be radially offset from the Venturicenter axis. An alternative definition of this arrangement is that thedownstream vane hub is centered on the Venturi center axis.

This embodiment enables the vane swirl mixer to effectively mix thereductant and the exhaust gas within the first flow device whileenabling a more centered stream of exhaust gas downstream of thedownstream vanes and thus allowing for a better efficiency of thecatalyst.

Each of the plurality of upstream vanes can be defined by an upstreamvane angle between an upstream vane hub center axis of the upstream vanehub and the plane of the upstream vane. The upstream vane hub centeraxis may be parallel to the Venturi center axis. The upstream vane anglefor each of the plurality of upstream vanes may be between forty-fivedegrees and ninety degrees and the upstream vane angle for one of theplurality of upstream vanes may be different from the upstream vaneangle for another of the plurality of upstream vanes.

Each of the plurality of downstream vanes can be defined by a downstreamvane angle between a downstream vane hub center axis of the downstreamvane hub and the plane of the downstream vane. The downstream vane hubcenter axis may be parallel to the Venturi center axis. The downstreamvane angle for each of the plurality of downstream vanes may be betweenforty-five degrees and ninety degrees and the downstream vane angle forone of the plurality of downstream vanes may be different from thedownstream vane angle for another of the plurality of downstream vanes.

Optionally each of the plurality of upstream vanes and/or the pluralityof downstream vanes is coupled to and conforms with the Venturi body.

The plurality of upstream vanes and the plurality of downstream vanescan be conduit straight vanes. Adjacent conduit straight vanes then forma conduit therebetween. The conduit has a streamwise direction that isdefined by the angle bisector of the planes of the adjacent conduitstraight vanes. A streamwise angle is defined between the plane of theconduit straight vane and a hub center axis of the conduit straight vanehub. The hub center axis of the conduit straight vane hub is parallel tothe Venturi center axis. The streamwise angle for each of the pluralityof conduit straight vanes may be between thirty degrees and ninetydegrees, inclusive, and the streamwise angle for one of the plurality ofconduit straight vanes may differ from the streamwise angle for anotherof the plurality of conduit straight vanes.

If a vane, be it an upstream vane or a downstream vane, is not astraight vane but has at least one of a twist in the radial directionand a curvature in the circumferential direction, then the plane of saidvane is determined by using at least one of an appropriate secant as areference.

Secants appropriate for the twist are to be drawn from the end of thevane at the hub to the radially outer end, at each of the leading andthe trailing edge of the vane. These are then projected in thecircumferential direction onto the radius at half the circumferentiallength of said vane so as to determine the angle bisector of these twoprojected secants. The angle bisector is then again projected in thecircumferential direction, back to the leading and the trailing edge.The plane defined by the two projected angle bisectors is used as thereference.

Secants appropriate for the curvature are to be drawn from the leadingedge to the trailing edge at both, the end of the vane at the hub andthe radially outer end. The plane defined by these two secants is usedas the reference.

Each of the plurality of conduit straight vanes can be coupled to andconform with the Venturi body such that each of the plurality of conduitstraight vanes cooperates with the Venturi body to form a conduit.

One of the plurality of conduit straight vanes can extend over anotherof the plurality of conduit straight vanes over an extension distance.The one of the plurality of conduit straight vanes has a width in thestreamwise direction. The extension distance may be between zero andseventy-five percent of the width in the streamwise direction of the oneof the plurality of conduit straight vanes.

The Venturi body can comprise an exhaust gas guide aperture disposedalong the Venturi body between the body inlet and the body outlet.

The exhaust gas guide aperture can be circular, alternativelyelliptical. The elliptical guide aperture can be dimensioned to have thesame area of opening as the circular exhaust gas guide aperture whileallowing for the Venturi body to require less length in the axialdirection of the mixer center axis and reducing the space between anupstream mixer and a downstream mixer. Reducing the spacing between themixers increases available volume between the downstream mixer and anSCR inlet, promotes a better decomposition and mixing of the reductantand improves the efficiency of the SCR system to reduce NOx emissions.

The vane swirl mixer can comprise a reductant doser through which thereductant is introduced into the vane swirl mixer. The doser may belocated about the exhaust gas guide aperture. If the latter is the case,the doser and the exhaust gas guide aperture are placed on a verticalmid-plane of the vane swirl mixer, directing the reductant towards themixer center axis. Alternatively the doser and the exhaust gas guideaperture are placed at an offset of a vertical mid-plane of the vaneswirl mixer, directing the reductant towards the Venturi walls. Thisoffset may correlate with an offset of the vane hub of the upstreammixer and/or the downstream mixer. If the doser is not located about theexhaust gas guide aperture, only the doser may be placed on a verticalmid-plane of the vane swirl mixer, directing the reductant towards themixer center axis, or alternatively placed at an offset of a verticalmid-plane of the vane swirl mixer, directing the reductant towards theVenturi walls. The offset may again correlate with an offset of the vanehubs of the upstream and/or the downstream mixers.

In one embodiment the Venturi center axis is radially offset from themixer center axis. Alternatively, and as also described below and shownin the accompanying drawings, the Venturi center axis is centered on themixer center axis.

The vane swirl mixer may be part of a multi-stage mixer such as it isshown in WO 2018/226626 A1.

BRIEF DESCRIPTION OF THE DRAWINGS

The details of one or more implementations are set forth in theaccompanying drawings and the description below. Other features,aspects, and advantages of the disclosure will become apparent from thedescription, the drawings, and the claims, in which:

FIG. 1 is a block schematic diagram of an example selective catalyticreduction system having an example reductant delivery system for anexhaust system;

FIG. 2 is a cross-sectional view of a vane swirl mixer and a doser;

FIG. 3 is front view of a mixer for a vane swirl mixer;

FIG. 4 is a cross-sectional view similar to FIG. 2, showing moredimensions of the vane swirl mixer;

FIG. 5 is a cross-sectional view of another vane swirl mixer;

FIG. 6 is a view onto an upstream face of a vane swirl mixer showing adesign which can be implemented in any of the vane swirl mixers shownand described herein;

FIG. 7A is a side view of another mixer for a vane swirl mixer;

FIG. 78 is another side view of the mixer shown in FIG. 7A;

FIG. 8 is a bottom perspective view of yet another mixer for a vaneswirl mixer;

FIG. 9 is a top perspective view of yet another mixer for a vane swirlmixer;

FIG. 10 is a side cross-sectional view of the mixer shown in FIG. 9;

FIG. 11 is a diagram showing the results of comparing a previous mixerwith an embodiment of a vane swirl mixer according to the invention.

It will be recognized that some or all of the figures are schematicrepresentations for purposes of illustration. The figures are providedfor the purpose of illustrating one or more implementations with theexplicit understanding that they will not be used to limit the scope orthe meaning of the claims.

DETAILED DESCRIPTION

Following below are more detailed descriptions of various conceptsrelated to, and implementations of, methods, apparatuses, and systemsfor flow distribution in an aftertreatment system. The various conceptsintroduced above and discussed in greater detail below may beimplemented in any of numerous ways, as the described concepts are notlimited to any particular manner of implementation. Examples of specificimplementations and applications are provided primarily for illustrativepurposes.

I. Overview

Internal combustion engines (e.g., diesel internal combustion engines,etc.) produce exhaust gases that are often treated within anaftertreatment system. This treatment often includes passing the exhaustgases through a catalyst. By providing the catalyst with a uniform flowof the exhaust gases, the efficiency of the catalyst, and therefore ofthe aftertreatment system, may be increased. Various components, such asbaffles, may be included within an aftertreatment system to change theflow of the exhaust gases into the catalyst. Conventional aftertreatmentsystems implement components that are difficult to scale (e.g., fordifferent applications, etc.) in a radial direction (e.g., variousdiameters, etc.) and in an axial direction (e.g., various lengths,various numbers of components, various configurations of components,etc.). For example, baffles may have complicated shapes that requireadvanced manufacturing techniques, and therefore substantial cost, toproduce. As a result, conventional aftertreatment systems do not offerthe flexibility necessary to be easily implemented in applications withvarying engine ratings and/or operating conditions. Further,conventional aftertreatment systems typically utilize complicatedcomponents that are expensive and require difficult and time intensivemanufacturing.

Implementations described herein relate to a vane swirl mixer thatincludes a plurality of flow devices that cooperate to provide acatalyst with a substantially uniform flow of exhaust gases andreductant, facilitate substantially uniform reductant distribution inthe exhaust gases downstream of the multi-stage mixer, and provide arelatively low pressure drop (e.g., the pressure of the exhaust gases atthe inlet of the multi-stage mixer less the pressure of the exhaustgases at the outlet of the multi-stage mixer, etc.), all in a relativelycompact space, compared to conventional aftertreatment systems. The flowdevices are relatively easy to manufacture compared to the complicateddevices currently used in aftertreatment systems. As a result, the vaneswirl mixer can be easily and readily scaled for various applicationswhile consuming less physical space than devices currently used inaftertreatment systems. The multi-stage mixer may be configured to dosethe exhaust gases with reductant, to cause an internal swirl flow thatmixes the reductant within the exhaust gases, and to create a uniformdistribution of the reductant within the uniform flow of the exhaustgases that flows into the catalyst. The vane swirl mixer may minimizespray impingement on wall surfaces due to swirl flow and relatively highshear stresses produced on the walls by the vane swirl mixer, therebymitigating deposit formation and accumulation within the vane swirlmixer and associated exhaust components.

In some implementations, the vane swirl mixer includes an exhaust gasguide that directs exhaust gases towards reductant ejected from areductant guide. The exhaust gases flow into the exhaust gas guide viaapertures that are disposed on at least part of the exhaust gas guide.The exhaust gases then assist the reductant in traveling into a flowdevice whereby the reductant and the exhaust gases may be subsequentlymixed via a swirl flow. The mixing may improve decomposition byutilizing the low pressure created by swirl flow and/or Venturi flow,enhance ordinary and turbulent diffusion, and elongate a mixingtrajectory of the exhaust gases and the reductant. Swirl flow refers toflow that swirls about a center axis of the vane swirl mixer and/or acenter axis of a flow device. Venturi flow refers to flow which occursdue to a low pressure region resulting from a reduction ofcross-sectional area and a local flow acceleration.

In some implementations, a flow device of the vane swirl mixer includesinternal plates that are positioned under the reductant guide. As thereductant flows into the flow device, the reductant contacts theinternal plates which facilitate mixing of the reductant within theexhaust gases by reducing the Stokes number of the reductant (e.g.,reductant droplets, etc.) via splashing.

The design features of the vane swirl mixer can be optimized to cater toa wide range of length to diameter ratio of the mixer (L/D) thusenabling both isotropic and anisotropic geometry scaling of the mixerdesign. The features may be combined to design a mixer with a biggerVenturi diameter while achieving the same flow profile.

II. Overview of Aftertreatment System

FIG. 1 depicts an aftertreatment system 100 having an example reductantdelivery system 110 for an exhaust system 190. The aftertreatment system100 includes a particulate filter, for example a diesel particulatefilter (DFF) 102, the reductant delivery system 110, a decompositionchamber or reactor 104, a SCR catalyst 106, and a sensor 150. In someembodiments, the SCR catalyst 106 includes an ammonia oxidation catalyst(ASC).

The DPF 102 is configured to remove particulate matter, such as soot,from exhaust gas flowing in the exhaust system 190. The DPF 102 includesan inlet, where the exhaust gas is received, and an outlet, where theexhaust gas exits after having particulate matter substantially filteredfrom the exhaust gas and/or converting the particulate matter intocarbon dioxide. In some implementations, the DPF 102 may be omitted.

The decomposition chamber 104 is configured to convert a reductant, suchas urea or DEF, into ammonia. The decomposition chamber 104 includes areductant delivery system 110 having a doser or dosing module 112configured to dose the reductant into the decomposition chamber 104 (forexample, via an injector such as the injector described below). In someimplementations, the reductant is injected upstream of the SCR catalyst106. The reductant droplets then undergo the processes of evaporation,thermolysis, and hydrolysis to form gaseous ammonia within the exhaustsystem 190. The decomposition chamber 104 includes an inlet in fluidcommunication with the DPF 102 to receive the exhaust gas containing NOxemissions and an outlet for the exhaust gas, NOx emissions, ammonia,and/or reductant to flow to the SCR catalyst 106.

The decomposition chamber 104 includes the dosing module 112 mounted tothe decomposition chamber 104 such that the dosing module 112 may dosethe reductant into the exhaust gases flowing in the exhaust system 190.The dosing module 112 may include an insulator 114 interposed between aportion of the dosing module 112 and the portion of the decompositionchamber 104 on which the dosing module 112 is mounted. The dosing module112 is fluidly coupled to one or more reductant sources 116. In someimplementations, a pump 118 may be used to pressurize the reductant fromthe reductant sources 116 for delivery to the dosing module 112.

The dosing module 112 and pump 118 are also electrically orcommunicatively coupled to a controller 120. The controller 120 isconfigured to control the dosing module 112 to dose reductant into thedecomposition chamber 104. The controller 120 may also be configured tocontrol the pump 118. The controller 120 may include a microprocessor,an application-specific integrated circuit (ASIC), a field-programmablegate array (FPGA), etc., or combinations thereof. The controller 120 mayinclude memory, which may include, but is not limited to, electronic,optical, magnetic, or any other storage or transmission device capableof providing a processor, ASIC, FPGA, etc. with program instructions.The memory may include a memory chip, Electrically Erasable ProgrammableRead-Only Memory (EEPROM), Erasable Programmable Read Only Memory(EPROM), flash memory, or any other suitable memory from which thecontroller 120 can read instructions. The instructions may include codefrom any suitable programming language.

The SCR catalyst 106 is configured to assist in the reduction of NOxemissions by accelerating a NOx reduction process between the ammoniaand the NOx of the exhaust gas into diatomic nitrogen and water. The SCRcatalyst 106 includes an inlet in fluid communication with thedecomposition chamber 104 from which exhaust gas and reductant arereceived and an outlet in fluid communication with an end of the exhaustsystem 190.

The exhaust system 190 may further include an oxidation catalyst (forexample a diesel oxidation catalyst (DOC)) in fluid communication withthe exhaust system 190 (e.g., upstream of the SCR catalyst 106 or theDPF 102) to oxidize hydrocarbons and carbon monoxide in the exhaust gas.

In some implementations, the DPF 102 may be positioned downstream of thedecomposition chamber or reactor 104. For instance, the DPF 102 and theSCR catalyst 106 may be combined into a single unit. In someimplementations, the dosing module 112 may instead be positioneddownstream of a turbocharger or upstream of a turbocharger.

The sensor 150 may be coupled to the exhaust system 190 to detect acondition of the exhaust gas flowing through the exhaust system 190. Insome implementations, the sensor 150 may have a portion disposed withinthe exhaust system 190; for example, a tip of the sensor 150 may extendinto a portion of the exhaust system 190. In other implementations, thesensor 150 may receive exhaust gas through another conduit, such as oneor more sample pipes extending from the exhaust system 190. While thesensor 150 is depicted as positioned downstream of the SCR catalyst 106,it should be understood that the sensor 150 may be positioned at anyother position of the exhaust system 190, including upstream of the DPF102, within the DPF 102, between the DPF 102 and the decompositionchamber 104, within the decomposition chamber 104, between thedecomposition chamber 104 and the SCR catalyst 106, within the SCRcatalyst 106, or downstream of the SCR catalyst 106. In addition, two ormore sensors 150 may be utilized for detecting a condition of theexhaust gas, such as two, three, four, five, or six sensors 150 witheach sensor 150 located at one of the foregoing positions of the exhaustsystem 190.

III. Example Vane Swirl Mixer

FIG. 2 depicts a vane swirl mixer 200 according to an exampleembodiment. While a vane swirl mixer 200 is described in this particularembodiment, it is understood that the relevant structure in this andsimilar embodiments may constitute other aftertreatment components suchas a SCR catalyst, a perforated tube, a pipe, a manifold, adecomposition chamber or reactor, a doser, a dosing module, and others.The vane swirl mixer 200 is configured to receive exhaust gases (e.g.,combustion gases from an internal combustion engine, etc.) and toprovide the exhaust gases downstream with a substantially uniform flowdistribution (e.g., flow profile, etc.). According to an exampleembodiment, the vane swirl mixer 200 is additionally configured toselectively dose the exhaust gases with a reductant (e.g., urea, dieselexhaust fluid (DEF), AdBlue®, etc.). Because the vane swirl mixer 200provides a substantially uniform flow distribution of the exhaust gasesand promotes mixing between exhaust gases and reductant, the vane swirlmixer 200 may also provide the exhaust gases downstream with asubstantially uniform reductant distribution (e.g., reductant profile,etc.).

The vane swirl mixer 200 includes a vane swirl mixer inlet 202 thatreceives the exhaust gases into the vane swirl mixer 200 and a vaneswirl mixer outlet 204 that provides the exhaust gases from the vaneswirl mixer 200. According to various embodiments, the vane swirl mixerinlet 202 receives the exhaust gases from a diesel particulate filter(e.g., the DPF 102, etc.) and the vane swirl mixer outlet 204 providesthe exhaust gases to the SCR catalyst 106.

Flows of fluid can be defined by a Reynolds number, which is related toa flow pattern of the fluid, and a Stokes number, which is related tothe behavior of particles suspended within the fluid. Depending on theReynolds number, the flow may be, for example, turbulent or laminar. Theflow of the exhaust gases into the vane swirl mixer inlet 202 can bedefined by a Reynolds number that is greater than 1e⁴, indicating thatthe flow of the exhaust gases is turbulent. Because the flow of theexhaust gases into the vane swirl mixer inlet 202 is turbulent,self-similarity exists. Depending on the Stokes number, particles may bemore or less likely to follow the flow of fluid. The flow of reductantcan be defined by a Stokes number that is on the order of one indicatingthat the reductant is unlikely to follow the flow of exhaust gases whichposes a problem in conventional mixing devices. Advantageously, the vaneswirl mixer 200 incorporates various components and devices herein whichcause the reductant to be mixed with the exhaust gases (e.g., byreducing the Stokes number of the reductant, etc.) such that thereductant is propelled through the vane swirl mixer 200 along with theexhaust gases. In this way, the vane swirl mixer 200 improves reductantmixing and reduces a risk associated with formation of deposits withinthe vane swirl mixer 200. In various embodiments, the vane swirl mixer200 is static and does not have components which move in response to thepassage of exhaust gases through the vane swirl mixer 200. In this way,the vane swirl mixer 200 may be less complex to manufacture and lessexpensive, and therefore more desirable, than aftertreatment componentswith moving components.

The vane swirl mixer 200 includes a plurality of flow devices thatsegment the vane swirl mixer 200 into a plurality of stages. Each of theplurality of flow devices is structured to alter the flow of the exhaustgases and reductant so that the plurality of flow devices cumulativelycauses the exhaust gases to obtain a target flow distribution and thereductant to obtain a target uniformity index (e.g., uniformitydistribution, etc.) at the vane swirl mixer outlet 204. Obtainingcertain flow distributions and reductant uniformities indices isimportant in the operation of an aftertreatment system. For example, itis desirable to obtain a uniform flow distribution and reductantuniformity index at an inlet of an SCR catalyst because such a flowdistribution allows the SCR catalyst to obtain a relatively highconversion efficiency.

As shown in FIG. 2, the vane swirl mixer 200 includes a first flowdevice 206.

The vane swirl mixer 200 includes a doser 214 and a port 216 throughwhich reductant (e.g., reductant droplets, etc.) from the doser 214 isselectively introduced into the vane swirl mixer 200. The vane swirlmixer 200 distributes the reductant uniformly within the exhaust gasesthat flow from the vane swirl mixer outlet 204 of the vane swirl mixer200. The port 216 is configured to guide, or assist in guiding, thereductant towards a center (e.g., a center axis, center of domain, etc.)of the vane swirl mixer 200 regardless of the conditions (e.g., flowrate, temperature, etc.) of the exhaust gases. For example, the port 216may have various shapes and/or thicknesses in order to guide thereductant towards the center of the multi-stage mixer 200. Alternativelythe port 216 can be configured to guide, or assist in guiding, thereductant offset from the center (e.g., a center axis, center of domain,etc.) of the vane swirl mixer. For example, the port 216 may be offsetfrom the center axis of the vane swirl mixer to direct the flow ofreductant towards the sidewall of the first flow device.

In some embodiments, the vane swirl mixer 200 also includes a reductantguide (e.g., nozzle, perforated tube, etc.) that at least partiallyshields the reductant from the flow of the exhaust gases from the vaneswirl mixer inlet 202 to facilitate guiding of the reductant to thecenter of the vane swirl mixer 200. The reductant guide extends from theport 216, receives the reductant from the doser 214, and provides thereductant into the vane swirl mixer 200 (e.g., at a center of the vaneswirl mixer 200, etc.). In various embodiments, the reductant guide isfrustoconical.

Due to the specific configuration and construction of the vane swirlmixer 200, the vane swirl mixer 200 is scalable and easily configurablewhile maintaining the ability to provide exhaust gases having a highlyuniform flow and reductant profile while minimizing a pressure dropexperienced by the exhaust gases as well as minimizing the likelihood ofdeposit (e.g., urea deposit, etc.) formation. As a result, the vaneswirl mixer 200 is capable of being configured for a target applicationat a lower cost than other mixers which are not readily adaptable (i.e.,due to the scalability and modularity of the vane swirl mixer 200,etc.). The vane swirl mixer 200 and components thereof are scalable inthe axial direction (e.g., in length, etc.) and the radial direction(e.g., in diameter, etc.).

By being scalable, the vane swirl mixer 200 can be utilized in variousapplications where different lengths and/or diameters of the vane swirlmixer 200 are desired. For example, the vane swirl mixer may be producedfor use with an aftertreatment system of a maritime vessel in one sizeand produced for use with an aftertreatment system of a dieselcommercial vehicle in another size.

Because of the flexibility of the vane swirl mixer 200, the vane swirlmixer 200 is capable of being manufactured at a lower cost thanconventional aftertreatment devices and of being easily tailored to manyspecific applications, thereby making the vane swirl mixer 200 moredesirable than conventional aftertreatment devices. Further, the vaneswirl mixer 200 may be configured for retrofit or drop-in applications.

The first flow device 206 is shown to include a funneling edge 300, aVenturi body 302, and a first support flange 304 (e.g., downstreamsupport flange, etc.). The funneling edge 300 is contiguous with theVenturi body 302 which is contiguous with the first support flange 304.The funneling edge 300 is configured to direct a majority of the exhaustgases from the vane swirl mixer inlet 202 into the Venturi body 302.However, the funneling edge 300 permits a portion of the exhaust gasesto initially circumvent the Venturi body 302 and enter a region betweenthe first flow device 206 and the vane swirl mixer 200. The funnelingedge 300 may have various angles relative to the center axis of the vaneswirl mixer 200 (e.g., ninety degrees, forty-five degrees, thirtydegrees, fifteen degrees, etc.). Additionally, the funneling edge 300may have various heights, as will be explained in more detail herein,relative to an outer edge of the body (e.g., relative to an outerdiameter of the body, etc.). By adjusting the height of the funnelingedge 300, more or less of the exhaust gases can be directed into thefirst flow device 206 and more or less of the exhaust gases can bedirected around the first flow device 206 (e.g., in a circumvented flow,etc.).

The Venturi body 302 may be circular, conical, frustoconical,aerodynamic, or other similar shapes. The first support flange 304functions to couple the first flow device 206 to the vane swirl mixer200. In various embodiments, the first support flange 304 provides aseal between the Venturi body 302 and the vane swirl mixer 200 such thatno exhaust gases may pass through or circumvent the first support flange304. As a result, the exhaust gases are redirected from the firstsupport flange 304 upstream for entry into the Venturi body 302.However, as explained in more detail herein, the first support flange304 in some embodiments has apertures through which the exhaust gasesmay pass to pass through the first flow device 206.

According to various embodiments, the diameter of the Venturi body 302is:0.25D ₀ ≤d _(V)≤0.9_(D)  (i)where the Venturi body 302 is defined by a diameter d_(V) and the vaneswirl mixer 200 is defined by an inner diameter D₀ greater than d_(V).The static pressure measured at the Venturi body 302 is given by

$\begin{matrix}{P_{C} = {P_{0} - {\left( {\left( \frac{D_{0}}{d_{V}} \right)^{4} - 1} \right)*\frac{1}{2}\rho\; v_{0}^{2}}}} & (2)\end{matrix}$where P_(C) is the absolute static pressure at the Venturi body 302,where P₀ is the absolute static pressure upstream of the Venturi body302 (e.g., as measured by a pressure transducer, as measured by asensor, etc.), where ρ is the density of the exhaust gases, and where v₀is the flow velocity upstream of the Venturi body 302 (e.g., as measuredby a sensor, etc.). Due to the difference is diameter between theVenturi body 302 and the vane swirl mixer 200, the Venturi body 302creates a low pressure region. The low pressure region enhances (e.g.,increases, expedites, etc.) decomposition of reductant (e.g., viaevaporation, via thermolysis, etc.), ordinary and turbulent diffusion,and mixing of reductant droplets.

The first flow device 206 also includes an upstream mixer 1106 having aplurality of upstream vanes 1108 and a plurality of upstream vaneapertures 1112 (see FIG. 3) interspaced therebetween to provide a swirlflow thereby creating additional low pressure regions and facilitatingmixing by elongating a mixing trajectory of the first flow device 206.The upstream mixer 1106 is configured to receive the exhaust gases fromthe vane swirl mixer inlet 202 and to provide the exhaust gases into theVenturi body 302. The upstream vanes 1108 are also attached to andconform to a upstream vane hub 1109 that is radially offset from thecenter axis of the Venturi body 302. The radial offset creates vaneswhich are variable in geometry, as the radial distance from the upstreamvane hub to the Venturi body differs depending on the radial direction.The offset can be in the range of0≤HU _(offset)≤0.25d _(V)  (3)where d_(V) is the Venturi diameter and HU_(offset) is the radial offsetof the upstream vane hub center from the Venturi center axis,respectively from the mixer center axis, as shown in FIG. 3.

The individual angles may be varied as well to obtain the desired flowsplit between different vanes. The variable geometry vane design can beoptimized to preferentially redirect flow to increase droplet trajectoryand thereby improving the mixing of the reductant droplets with theexhaust gas as well as achieving high shear velocity on the Venturiwalls to minimize the likelihood of deposit (e.g., urea deposit, etc.)formation.

The upstream vanes 1108 are static and do not move within the Venturibody 302. In this way, the upstream mixer 1106 may be less complex tomanufacture and less expensive, and therefore more desirable, thanaftertreatment components with complicated components that are expensiveand require difficult and time intensive manufacturing. Rather thanconfining the flow of exhaust gases into a single path to create a swirlflow, the upstream vanes 1108 provide several openings between adjacentupstream vanes 1108, such that each of the upstream vanes 1108independently swirls the exhaust gases and such that the upstream vanes1108 collectively form the swirl flow in the exhaust gases.

The upstream vanes 1108 are positioned (e.g., curved, angled, bent,etc.) to cause a swirl (e.g., mixing, etc.) flow of the exhaust gasesand the reductant to form a mixture. In various embodiments, theupstream vanes 1108 are substantially straight (e.g., substantiallydisposed along a plane, having a substantially constant slope along theupstream vane 1108, etc.). In other embodiments, the upstream vanes 1108are curved (e.g., not substantially disposed along a plane, havingdifferent slopes along the upstream vane 1108, having edges which arecurved relative to the remainder of the upstream vane 1108, etc.). Instill other embodiments, adjacent upstream vanes 1308 are positioned soas to extend over one another. In these embodiments, the upstream vanes1108 may be straight and/or curved. In embodiments with multipleupstream vanes 1108, each upstream vane 1108 may be independentlyconfigured so that the upstream vanes 1108 are individually tailored toachieve a target configuration of the first flow device 206 such thatthe vane swirl mixer 200 is tailored for a target application.

Each of the upstream vanes 1108 is defined by a vane angle (e.g.,relative to a vane hub center axis, etc.) that is related to the swirlproduced by that upstream vane 1108. The vane angle may be definedbetween a vane edge line (e.g. the line co-axial with the radiallyoutermost circumferential edge of the angled part of a vane) and thevane hub center axis. If the vane edge line and the vane hub center axisdo not intersect, the vane angle is defined between the vane hub centeraxis and a plane defined by the vane edge line and a point ofintersection of the vane hub center axis with a plane formed by theupstream edges of the vanes. The vane angle for each of the upstreamvanes 1108 may be different from the vane angle for any of the others ofthe upstream vanes 1108. According to various embodiments, the firstflow device 206 includes upstream vanes 1108 that have a vane angle ofbetween forty-five and ninety degrees. Similarly, the first flow device206 may include any number of the upstream vanes 1108. In someembodiments, the first flow device 206 includes between four and twelveupstream vanes 1108.

The upstream vane apertures 1112 collectively define an open area A_(I).However, the size of the upstream vane apertures 1112 is related to, inpart, the diameter of the upstream vane hub 1109. According to variousembodiments, the diameter of the upstream vane hub 1109 is given by0.05d _(V) ≤D _(H)≤0.25d _(V)  (4)where D_(H) is the diameter of the upstream vane hub 1109. Inapplication, any of the number of the upstream vanes 1108, the vaneangles of the upstream vanes 1108, and the diameter of the upstream vanehub 1109 may be varied to optimize improvements in the flow of theexhaust gases and the reductant, the improvements in the mixing of thereductant, and the improvements in minimizing pressure drop. Theupstream mixer 1106 may be configured such that the upstream vanes 1108are symmetrically or asymmetrically disposed about the upstream vane hub1109.

The first flow device 206 includes a downstream mixer 309 (see FIG. 2)that includes downstream vanes 310. It is understood that the downstreammixer 309 as shown and described with reference to FIG. 2 may beincluded in any of the embodiments of the vane swirl mixer 200 discussedherein.

The downstream vanes 310 are attached to an downstream vane hub 313 thatis not radially offset from the center axis of the vane swirl mixer 200.However, the downstream vane hub 313 may optionally also be offset inthe range of0≤HD _(offset)≤0.25d _(V)  (5)where d_(V) is the Venturi diameter and HD_(offset) is the radial offsetof the downstream vane hub center from the Venturi center axis,respectively from the mixer center axis, as shown in FIG. 3. HD_(offset)may have the same amount and the same radial direction as the offsetHU_(offset), of the upstream vane hub, however it may also beindependent from the offset of the upstream vane hub. This offset againcreates vanes which are variable in geometry, as the radial distancefrom the downstream vane hub to the Venturi body differs depending onthe radial direction. The downstream vane hub 313 is coupled to theVenturi body 302 (e.g., via members interspacing adjacent downstreamvanes 310, etc.). The downstream vanes 310 may be similar to ordifferent from the upstream vanes 1108. Tips (e.g., outermost surfaces,etc.) of each of the downstream vanes 310 may be spaced from the Venturibody 302 by an air gap such that the exhaust gases can pass between thetips of each of the downstream vanes 310 and the Venturi body 302.

The downstream mixer 309 includes a plurality of downstream vaneapertures interspaced between the plurality of downstream vanes 310. Inthis way, the plurality of upstream vanes and the plurality ofdownstream vane apertures provide a swirl flow within the first flowdevice 206. The downstream vanes 310 are attached to and conform to theVenturi body 302 such that the exhaust gases can only exit the Venturibody 302 through the downstream vane apertures. The plurality ofupstream vane apertures cooperate with the plurality of downstream vanes310 to provide the exhaust gases into the first flow device 206 with aswirl flow that facilitates mixing of the reductant and the exhaustgases. The downstream vanes 310 may be configured to create a swirl flow(e.g., co-swirl flow, counter-swirl flow, etc.) that is separate fromthe swirl flow created by the upstream vanes 1108. In this way, thedownstream vanes 310 can be utilized to increase or decrease the totalswirl created by the first flow device 206. Further, the downstreamvanes 310 may increase mixing of the reductant and the exhaust gaseswithin the Venturi body 302.

In the embodiment shown in FIG. 2, the upstream vanes 1108 are locatedupstream of where the reductant is introduced while the downstream vanes310 are located downstream of where the reductant is introduced. In thisembodiment, the upstream vanes 1108 create a first swirl flow in a firstdirection and the downstream vanes 310 create a second swirl flow in asecond direction that may be the same as the first direction (e.g.,co-swirl flow, etc.) or opposite to the first direction (e.g.,counter-swirl flow, etc.). Rather than confining the flow of exhaustgases into a single path to create a swirl flow, the upstream varies1108 provide several openings between adjacent upstream vanes 1108, suchthat each of the upstream vanes 1108 independently swirls the exhaustgases and such that the upstream vanes 1108 collectively form the swirlflow in the exhaust gases.

The upstream vanes 1108 and/or the downstream vanes 310 may beconstructed (e.g., manufactured, made, etc.) using sheet metal. (e.g.,aluminum sheets, steel sheets, etc.) in various applications. Forexample, the upstream vanes 1108 and/or the downstream vanes 310 may beconstructed through stamping, punching, laser cutting, waterjet cutting,bending and/or welding operations.

FIG. 3 shows an example of swirl mixer vanes with different geometries.The vane hub has been moved in the direction of the vane edge of vaneV1, thereby creating vanes 1108 with vane edges increasing in lengthsfrom vane edge length L1 to vane edge length L4 (movingcounter-clockwise). Vane V4 is also bent by a larger angle compared toV1, V2 and V3 thus creating a bigger opening and allowing a higherfraction of the overall flow to go through it. This is depicted in FIG.3 by the plus symbol “+” (indicating a smaller vane open angle) at thegap between V4 and V5 and the minus symbol “−” (indicating a larger vaneopen angle) at the gaps between vanes V1 and V2, V2 and V3 and V3 and V4respectively. The vane angle may be different for each of the vanes ofthe vane swirl mixer.

FIG. 3 illustrates a combined upstream vane 1700 in one embodiment. Thecombined upstream vane 1700 may be formed in a variety of manners. Invarious embodiments, the combined upstream vane 1700 is formed from alarge upstream vane 1108 which is folded flat (e.g., at a vane angle ofninety degrees, etc.). In these embodiments, the large upstream vane1108 may be twice the size of the other upstream vanes 1108. In otherembodiments, the combined upstream vane 1700 is formed from a firstupstream vane V5 and a second adjacent and contiguous upstream vane V6.In these embodiments, the first adjacent upstream vane V5 and the secondadjacent upstream vane V6 each have a vane angle of ninety degrees andthen the first adjacent upstream vane V5 and the second adjacentupstream vane V6 are either joined directly (e.g., adjacent edges ofeach of the first adjacent upstream vane V5 and the second adjacentupstream vane V6 are attached together, etc.) or indirectly (e.g., aspanning member is attached to each of the first adjacent upstream vaneV5 and the second adjacent upstream vane V6, etc.).

The vane edges may further be at an angle γ to a doser injection axis215 that is directed towards the center of the Venturi, the angle γbeing defined between the doser injection axis 215 and the radial edgeof a vane which is circumferentially nearest. The angle γ can be between±360/2n, where n is the number of vanes (counting both open and closedvanes). In the embodiment illustrated in FIG. 3 the angle γ is definedbetween the doser injection axis 215 and the edge of vane V5 nearest tothe doser injection axis. In a vane swirl mixer with n=6, as depicted inFIG. 3, the angle γ can be between −30 degrees (counter-clockwisedirection in FIG. 3) and +30 degrees (clockwise direction in FIG. 3).For the sake of calculation, combined vanes may always be regarded asindividual closed vanes, similar to the vanes V5 and V6 depicted in FIG.3.

FIG. 4 illustrates a cross-sectional view of the vane swirl mixer 200.The upstream mixer 1106 is located upstream of the exhaust gas guideaperture 306 (see also FIG. 2) and the first flow device 206 is locateddownstream of the exhaust gas guide aperture 306. The upstream mixer1106 functions to create a swirl flow of the exhaust gases within thefirst flow device 206 downstream the upstream mixer 1106. The swirl flowcreated by the upstream mixer 1106 facilitates distribution of thereductant in the exhaust gases between the upstream mixer 1106 and thedownstream vanes 310 such that the reductant is substantially evenlydistributed within the exhaust gases when the exhaust gases encounterthe downstream vanes 310. Additionally, the swirl flow created by theupstream mixer 1106 creates a relatively large shear at the Venturi body302 (e.g., the portion of the Venturi body 302 between the upstreamvanes 1108 and the downstream vanes 310, etc.) to reduce the formationof a film, and therefore the accumulation of deposits, along the Venturibody 302. The downstream vanes 310 function to impart a swirl flow onthe exhaust gases and entrained reductant downstream of the first flowdevice 206. This swirl flow causes the exhaust gases to be relativelyuniform (e.g., in terms of reductant composition, etc.) downstream ofthe first flow device 206, such as at the vane swirl mixer outlet 204(e.g., proximate an inlet of the SCR catalyst 106, etc.).

The Venturi body 302 is defined by a body center axis A_(V). The Venturibody 302 is centered on (e.g., a centroid of the Venturi body 302 iscoincident with, etc.) the body center axis A_(V). The upstream vane hub1109 is centered on an offset axis h_(r). The radial offset HU_(offset),as can be seen in FIG. 3, of the offset axis h_(r) causes any reductantbuild up on the Venturi body 302 (e.g., non-uniform distribution of thereductant in the exhaust gases within the first flow device 206, etc.)to be substantially redistributed to the exhaust gases downstream of thefirst flow device 206. While the offset axis h_(r) is offset from theVenturi center axis A_(V) away from the port 216 by the radial offsetHU_(offset) in FIG. 4, it is understood that the offset axis h_(r) maybe offset from the Venturi center axis A_(V) towards the port 216 by theradial offset HU_(offset), or offset from the Venturi center axis A_(V)towards the Venturi body 302 in any radial direction (e.g., orthogonallyto the port 216, at an angle to a doser axis, etc.) by the radial offsetHU_(offset).

The Venturi body 302 has a body inlet 1304 and a body outlet 1306. Theinlet has a diameter d_(V) and the outlet has a diameter d_(S) which istypically less than the diameter d_(V). The diameter d_(V) and thediameter d_(S) are each less than the diameter D₀ of the vane swirlmixer 200. In various embodiments, the vane swirl, mixer 200 and thefirst flow device 206 are configured such that0.4D ₀ ≤d _(V)≤0.9D ₀  (6)0.7d _(V) ≤d _(S) ≤d _(V)  (7)0≤h _(r)≤0.1D ₀  (8)

In various embodiments, the first support flange 304 does not protrudeinto the Venturi body 302 (e.g., the first support flange 304 defines anaperture contiguous with the Venturi body 302 and having a diameterequal to the diameter d_(S), etc.).

In various embodiments, the funneling edge 300 radially protrudes fromthe body inlet 1304 towards the vane swirl mixer 200 a distance h_(i).In various embodiments, the first flow device 206 is configured suchthat0≤h _(i)≤0.1d _(V)  (9)

By varying the distance h_(i), the flows of the exhaust gas into thefirst flow device 206 and/or the exhaust gas guide aperture 306 may beoptimized.

The reductant flows from the port 216 through the exhaust gas guideaperture 306. The exhaust gas guide aperture 306 is generally circularand defined by a diameter d_(e). In various embodiments, the first flowdevice 206 is configured such that

$\begin{matrix}{d_{e} = {\left( {D_{0} - d_{V} - {2h_{r}}} \right)*{\tan\left( \frac{\alpha + \delta}{2} \right)}}} & (10)\end{matrix}$where5°≤δ≤20°  (11)where δ is a margin that is selected based on the configuration of thefirst flow device 206 and where α is a spray angle of a nozzle directingthe flow of exhaust gas. In some embodiments the exhaust gas guideaperture 306 is elliptical. In these embodiments, the diameter d_(e) maybe a major axis (e.g., as opposed to a minor axis, etc.) of the exhaustgas guide aperture 306.

The first flow device 206 is also defined by a spacing L_(h) between theupstream mixer 1106 and the downstream mixer 309. The spacing L_(h) canbe a fixed distance between the upstream mixer and the downstream mixerindependent of the diameter D₀ of the vane swirl mixer 200 and the inletdiameter d_(V) or the outlet diameter d_(S). This allows for a widerange of scaling options of the mixer diameters while keeping theoverall length of the vane swirl mixer 200 minimal. Previous exhaust gasmixers were not able to scale the diameter of the exhaust gas mixerindependently of the mixer length. This allows for an increased exhaustgas mixer diameter without increasing the length required to fit thevane swirl mixer within the exhaust unit. The diameter D₀ of the vaneswirl mixer 200 and the Venturi inlet diameter d_(V) can be changedbased on the space claim and the performance targets of the application.The diameter D₀ of the vane swirl mixer 200 may range from 8 inches(20.32 cm) to 15 inches (38.1 cm) while the Venturi inlet diameter d_(V)may range from 2 inches (5.08 cm) to 13.5 inches (34.29 cm) whilekeeping the spacing L_(h) a constant.

In various embodiments, the first flow device 206 is configured suchthat

$\begin{matrix}{d_{e} \leq L_{h} \leq \frac{d_{e}\left( {D + d_{v} - {2*{HU}_{offset}}} \right)}{\left( {D - d_{v} - {2*{HU}_{offset}}} \right)}} & (12)\end{matrix}$

The Venturi body 302 includes a shroud 1308. It is understood that theshroud 1308 as shown and described with reference to FIG. 4 may beincluded in any of the embodiments of the vane swirl mixer 200 discussedherein.

The shroud 1308 defines a downstream end of the Venturi body 302 and istherefore defined by the diameter d_(S). In various embodiments, theshroud 1308 is cylindrical or conical (e.g., frustoconical, etc.) inshape. The shroud 1308 may facilitate a reduction in stratification ofthe exhaust gases that occurs from centrifugal force created by thedownstream mixer 309. Additionally, the shroud 1308 may providestructural support to the downstream mixer 309, such as when thedownstream vanes 310, in addition to the downstream vane hub 313, areattached to the shroud 1308 (e.g., such that the downstream vanes 310conform to the shroud 1308, etc.). When the downstream vanes 310 areattached to the shroud 1308, the downstream vanes 310 may provide a moredirected swirl flow (e.g., along a target trajectory, etc.) by removingleak paths, thereby improving mixing performance (e.g., the ability ofthe downstream mixer 309 to mix the reductant and exhaust gases, etc.)and reducing the accumulation of deposits downstream of the downstreammixer 309 (e.g., in the shroud 1308, in the exhaust component downstreamof the vane swirl mixer 200, etc.). Furthermore, the shroud 1308substantially prevents leakage flow and liquid film accumulation andmitigates the formation of deposits within the first flow device 206(e.g., on the Venturi body 302, etc.) and/or the vane swirl mixer 200.The shroud 1308 is defined by an angle Φ relative to an axis parallel tothe Venturi center axis A_(V) and the mixer center axis. In variousembodiments, the first flow device 206 is configured such thatΦ≤50°  (13)

In various embodiments, the first flow device 206 is configured suchthat

$\begin{matrix}{L_{S} = \frac{d_{v} - d_{S}}{2*\tan\;\Phi}} & (14)\end{matrix}$where L_(S) is the length of the shroud 1308. Where the shroud 1308 iscylindrical, the diameter d_(S) is equal to the diameter d_(v) and0.02d _(v) ≤L _(S)≤0.25d _(v)  (15)

In some embodiments, at least one of the flow devices of the vane swirlmixer 200 is angled relative to the mixer center axis. For example, thefirst flow device 206 may be configured such that the Venturi centeraxis A_(V) is tilted up from (e.g., angled at a positive angle relativeto, etc.) the mixer center axis or such that the Venturi center axisA_(V) is tilted down from (e.g., angled at a negative angle relative to,etc.) the mixer center axis.

The upstream vanes 1108 may be spaced from the Venturi body 302 by a gapg. In various embodiments, the first flow device 206 is configured suchthat0≤g≤0.15d _(V)  (16)

The gap g may mitigate accumulation of reductant deposits on the Venturibody 302. The gap g functions to create a substantially axial flow ofexhaust gases directed along the Venturi body 302 (e.g., on the innersurfaces of the Venturi body 302, etc.). In this way, the gap g maybalance flow (e.g., a main tangential flow, etc.) of the exhaust gasesthrough the upstream vanes 1108 with the aforementioned axial flow and aflow of the exhaust gases around the first flow device 206. Instead of,or in addition to, the gap g, the upstream vanes 1108 may include slots(e.g., thin slots) or holes through which the exhaust gases may flow.For example, each of the upstream vanes 1108 may include a slotcontiguous with an outermost edge of the upstream vane 1108. In thisexample, the exhaust gases may flow through the slot and against theVenturi body 302 proximate the slot, thereby providing benefits similarto those of the gap g.

In FIG. 4, the downstream vanes 310 are shown in contact with the shroud1308 such that no gap exists between at least a portion of each of thedownstream vanes 310 and the shroud 1308. In an example embodiment, thetip (e.g., the most radially outward surface, etc.) of each of thedownstream vanes 310 is welded (e.g., fused, etc.) to the shroud 1308.

In some embodiments, the downstream vanes 310 may be spaced from theshroud 1308 by a gap g_(v). In various embodiments, the first flowdevice 206 is configured such that0≤g≤0.15d _(V)  (17)

The gap g_(v) may mitigate accumulation of reductant droplets on theshroud 1308. The gap g_(v) functions to create a substantially axialflow of exhaust gases directed along the shroud 1308 (e.g., on innersurfaces of the shroud 1308, etc.). Instead of, or in addition to, thegap g_(v), the downstream vanes 310 may include slots (e.g., thin slots)or holes through which the exhaust gases may flow. For example, each ofthe downstream vanes 310 may include a slot contiguous with an outermostedge of the downstream vane 310. In this example, the exhaust gases mayflow through the slot and against the shroud 1308 proximate the slot,thereby providing benefits similar to those of the gap g.

In some embodiments, the tip of each of the upstream vanes 1108 isattached (e.g., welded, coupled, etc.) to the Venturi body 302 (e.g.,such that the upstream vanes 1108 conform to the Venturi body 302,etc.). When the upstream vanes 1108 are attached to the Venturi body302, the upstream vanes 1108 may provide a more directed swirl flow(e.g., along a target trajectory, etc.) by removing leak paths, therebyimproving mixing performance (e.g., the ability of the upstream mixer1106 to mix the reductant and exhaust gases, etc.) and reducing theaccumulation of deposits downstream of the upstream mixer 1106 (e.g., inthe Venturi body 302, on the downstream mixer 309, in the exhaustcomponent downstream of the vane swirl mixer 200, etc.). In FIG. 4, theupstream vanes 1108 are shown in contact with the Venturi body 302 suchthat no gap exists between at least a portion of each of the upstreamvanes 1108 and the Venturi body 302.

Each of the upstream vanes 1108 is defined by an upstream vane anglerelative to an upstream vane hub center axis of the upstream vane hub1109 of the upstream vanes 1108. Similarly, the downstream vane anglefor each of the downstream vanes 310 is defined relative to a downstreamvane hub center axis of the downstream vane hub 313. The upstream vaneangle for each of the upstream vanes 1108 may be different from theupstream vane angle for any of the others of the upstream vanes 1108. Invarious embodiments, the upstream vane angle for each of the upstreamvanes 1108 is between forty five degrees and ninety degrees, inclusive,relative to a downstream vane hub center axis of the downstream vane hub313 and the downstream vane angle for each of the downstream vanes 310is between forty five degrees and ninety degrees, inclusive. Theupstream vane angle for each of the upstream vanes 110 may be selectedsuch that the first flow device 206 is tailored for a targetapplication. Similarly, the downstream vane angle for each of thedownstream vanes 310 may be selected such that the first flow device 206is tailored for a target application. The upstream mixer 1106 may beconfigured such that the upstream vanes 1108 are symmetrically orasymmetrically disposed about the upstream vane hub 1109.

The upstream vane angle may be different for each of the upstream vanes1108 and the downstream vane angle may be different from each of thedownstream vanes 310. Selection of the upstream vane angle for each ofthe upstream vanes 1108 and the downstream vane angle for each of thedownstream vanes 310 may be made so as to create asymmetric swirl of theexhaust gases, to direct flow of the exhaust gases (e.g., towards atarget location in the vane swirl mixer 200, etc.), to more uniformlydistribute reductant within the exhaust gases, and to reduce depositswithin the first flow device 206 (e.g., on the Venturi body 302, etc.)and/or the vane swirl mixer 200.

FIG. 5 illustrates the flow of exhaust gases within the vane swirl mixer200 and illustrates how the exhaust gases behave when encountering thefirst flow device 206. The exhaust gases upstream of the first flowdevice 206 are divided into a main flow 1900 (e.g., Venturi flow, swirlflow, etc.) and a circumvented flow 1902 (e.g., exhaust assist flow,etc.). The main flow 1900 is provided into the first flow device 206(e.g., the main flow 1900 is funneled into the Venturi body 302 by thefunneling edge 300, etc.).

In some embodiments, the circumvented flow 1902 is 5-40%, inclusive, ofthe sum of the circumvented flow 1902 and the main flow 1900 (e.g., thetotal flow, etc.). In these embodiments, the main flow 1900 is 60-95%,inclusive, of the sum of the circumvented flow 1902 and the main flow1900 (e.g., the total flow, etc.). Accordingly, where the vane swirlmixer 200 includes six upstream vanes 1108, each gap between adjacentupstream vanes 1108 receives 6-16%, inclusive, of the sum of thecircumvented flow 1902 and the main flow 1900 (e.g., the total flow,etc.).

The main flow 1900 and the circumvented flow 1902 define a flow split.The flow split is a ratio of the circumvented flow 1902 to the main flow1900, represented as a percentage of the main flow 1900. The flow splitis a function of the diameter d_(V), the diameter d_(e), and thedistance h_(i). By varying the flow split, an optimization of targetmixing performance (e.g., based on a computational fluid dynamicsanalysis, etc.) of the first flow device 206, target deposit formation(e.g., a target amount of deposits formed over a target period of time,etc.), and target pressure drop (e.g., a comparison of the pressure ofthe exhaust gases upstream of the first flow device 206 and a pressureof the pressure of the exhaust gases downstream of the first flow device206, etc.), can be performed such that the first flow device 206 can betailored for a target application. In various embodiments, the flowsplit ratio is between five percent and seventy percent, inclusive. Thatis, the circumvented flow 1902 is between five percent and seventypercent, inclusive, of the main flow 1900.

The circumvented flow 1902 is divided into a diverted flow 1904 and anisolated flow 1906. The diverted flow 1904 is mixed with the reductantprovided to the first flow device 206 through the port 216. For example,the circumvented flow 1902 may enter the Venturi body 302 as thediverted flow 1904 directly through the exhaust gas guide aperture 306.

The isolated flow 1906 does not enter the first flow device 206immediately and instead encounters the first support flange 304. Invarious embodiments, the first support flange 304 is sealed against thevane swirl mixer 200 and the Venturi body 302, and does not permit thepassage of the isolated flow 1906 through or around the first supportflange 304. In these embodiments, the isolated flow 1906 flows backtowards the body inlet 1304. As the isolated flow 1906 flows backtowards the body inlet 1304, a portion of the isolated flow 1906 mayflow into the Venturi body 302 as the diverted flow 1904. Other portionsof the isolated flow 1906 may flow past the exhaust gas guide aperture306 and enter the Venturi body 302 through the body inlet 1304 as themain flow 1900. In other embodiments, the first support flange 304includes at least one aperture permitting the passage of the exhaustgases therethrough, thereby allowing at least a portion of the isolatedflow 1906 to bypass the body entirely. This portion of the isolated flow1906 would mix with the main flow 1900 downstream of the body outlet1306 (e.g., after the main flow 1900 has combined with the diverted flow1904 and the reductant within the Venturi body 302, etc.).

According to the embodiment shown in FIG. 5, the main flow 1900 ispassed through the upstream vanes 1108, mixed with reductant and thediverted flow 1904, and then passed through the downstream vanes 310,through the shroud 1308, and out of the body outlet 1306.

FIG. 6 illustrates a second support flange 2100 according to an exampleembodiment. It is understood that the second support flange 2100 asshown and described with reference to FIG. 6 may be included in any ofthe embodiments of the vane swirl mixer 200 discussed herein. The secondsupport flange may be coupled to the Venturi body upstream of theexhaust gas guide aperture 306, as shown in FIG. 6, which illustrates aview of an upstream face of the first flow device 206. The secondsupport flange 2100 may also be coupled to the Venturi body 302downstream of the exhaust gas guide aperture 306 but upstream of thefirst support flange 304. The second support flange 2100 may also becoupled to the Venturi body 302 upstream of the exhaust gas guideaperture 306. In some embodiments, the second support flange 2100 iscontiguous with the funneling edge 300 (e.g., the funneling edge 300 isa part of the second support flange 2100, etc.).

The second support flange 2100 includes a plurality of second supportflange apertures 2102 (e.g., holes, passages, pathways, etc.). Thecircumvented flow 1902 traverses the second support flange 2100 throughthe second support flange apertures 2102. In various embodiments, thesecond support flange 2100 may include one, two, three, four, five, six,or more second support flange apertures 2102.

Each of the second support flange apertures 2102 is separated from anadjacent one of the second support flange apertures 2102 by a secondsupport flange connector 2104 (e.g., arm, rod, etc.). The second supportflange connector 2104 is integrated with the second support flange 2100and is coupled to the vane swirl mixer 200 and to the first flow device206. In one example, the second support flange connector 2104 is coupledto the Venturi body 302 while the first support flange 304 is coupled tothe shroud 1308. In some embodiments, the second support flange 2100 iscoupled to the funneling edge 300 (e.g., the funneling edge 300 is apart of the second support flange 2100, etc.).

The second support flange 2100 does not protrude into the body inlet1304 (e.g., the second support flange 2100 defines an aperturecontiguous with the Venturi body 302 and having a diameter equal to thediameter d_(V), etc.). In various embodiments, the second support flange2100 includes one, two, three, four, five, six, or more second supportflange connectors 2104. In some embodiments, the number of secondsupport flange apertures 2102 is equal to the number of second supportflange connectors 2104.

In this embodiment, the doser 214 is aligned with the center of theVenturi. The doser 214 can also be aligned with the offset upstream vanehub 1109 or downstream vane hub 313. Alternatively, the doser 214 mayalso be aligned with the Venturi axis, however a doser nozzle may directthe flow of the reductant towards the offset upstream vane hub center1109 and the corresponding axis h_(r).

The second support flange apertures 2102 are distributed about thecircumference of the Venturi body 302. In this embodiment the largestsecond support flange aperture 2102 is twice the size of the other foursecond support flange apertures 2102 and is arranged so that thecircumvented flow 1902 is directed towards the doser 214 and the exhaustgas guide aperture 306 unhindered. To this end, the largest secondsupport flange aperture 2102 may preferably further be circumferentiallycentered on the doser injection axis 215. Alternatively the secondsupport flange apertures 2102 are arranged such that no second supportflange connectors 2104 are located upstream of the doser 214 and theexhaust gas guide aperture 306 in the direction of the circumvented flow1902.

FIGS. 7A and 7B illustrate a conduit straight vane mixer 2200 accordingto an example embodiment. It is understood that the conduit straightvane mixer 2200 as shown and described with reference to FIGS. 7A and 7Bmay be included in any of the embodiments of the vane swirl mixer 200discussed herein.

The conduit straight vane mixer 2200 includes a plurality of conduitstraight vanes 2202 each coupled to and conforming with a conduitstraight vane hub 2206. Rather than forming apertures between any of theconduit straight vanes 2202, as are formed between adjacent upstreamvanes 1108, any of the conduit straight vanes 2202 and any combinedconduit straight vanes form conduits therebetween. As explained herein,a conduit is a closed pathway with a single inlet and a single outlet(e.g., is bounded on four out of six sides, etc.).

While not shown, tips (e.g., outermost edges, etc.) of each of theconduit straight vanes 2202 is coupled to and conforms with the shroud1308 or Venturi body 302. The trailing edge of one of the conduitstraight vanes 2202 or combined conduit straight vanes extends beyondthe leading edge of an adjacent one of the conduit straight vanes 2202or combined conduit straight vanes in a streamwise direction S_(t) andthereby confines a flow of exhaust gases in a spanwise direction S_(P).The streamwise direction S_(t) is tangential to a plane of the conduitstraight vane at the tip of the leading edge while the spanwise S_(P) isnormal to (e.g., orthogonal to, etc.) the streamwise direction S_(t)respectively to the plane of the conduit straight vane at the tip of theleading edge. This spanwise confinement combined with the conformingcoupling of the conduit straight vanes 2202 to the conduit straight vanehub 2206 and to the shroud 1308 (both of which confine flow in wallnormal directions) create a conduit for each of the conduit straightvanes 2202. Each conduit has four sides: a first defined by one conduitstraight vane 2202 or combined conduit straight vane, a second definedby the conduit straight vane hub 2206, a third defined by the shroud1308 or Venturi body 302, and a fourth defined by another conduitstraight vane 2202 or combined conduit straight vane. Each conduitefficiently directs the exhaust gases. In various embodiments, theconduit straight vane mixer 2200 is utilized in the first flow device206 in place of the downstream mixer 309. In other embodiments, theconduit straight vanes 2202 are not coupled to the shroud 130 andinstead are coupled to and conform with the Venturi body 302. In theseembodiments, the conduit straight vanes 2202 are instead coupled to andconform with the Venturi body 302. In such embodiments, the conduitstraight vane mixer 2200 may be utilized in place of or in addition tothe upstream mixer 1106.

In some embodiments, the conduit straight vane mixer 2200 includes two,three, four, five, six, seven, eight, or more conduit straight vanes2202. Like the upstream vanes 1108, each of the conduit straight vanes2202 is defined by a blade angle. These blade angles may be varied suchthat a combined conduit straight vane (not shown) may be formed asdescribed with regard to the combined upstream vane 1700 above. In someembodiments, the conduit straight vane mixer 2200 includes one, two,three or more of the combined conduit vanes. In other embodiments, theconduit straight vane mixer 2200 does not include the combined conduitvane. In an example embodiment, the conduit straight vane mixer 2200includes three of the conduit straight vanes 2202 and one combinedconduit straight vane.

The conduit straight vane hub 2206 is offset from the mixer center axisby HU_(offset), as detailed above.

Each of the conduit straight vanes 2202 and combined conduit straightvane extend over an adjacent conduit straight vane 2202 or combinedconduit straight vane. This distance is shown in FIG. 7A as extensiondistance E_(sw). The extension distance E_(sw) is expressed as apercentage of the width in the streamwise direction S_(t) of a singleconduit straight vane 2202 at a given distance from the axis (e.g., theVenturi center axis A_(V), the mixer center axis, etc.) upon which theconduit straight vane hub 2206 is centered. In various embodiments, thisextension distance E_(sw) is between 0% and 75%, inclusive, of the widthin the streamwise direction S_(t) of a single conduit straight vane 2202at a given distance from the axis upon which the conduit straight vanehub 2206 is centered. The extension distance E_(sw) may differ for eachof the individual conduit straight vanes 2202 (e.g., one conduitstraight vane 2202 having an extension distance E_(sw) of 25%, anadjacent conduit straight vane 2202 having an extension distance E_(sw)of 40%, another conduit straight vane 2202 having an extension distanceE_(sw) of 75%.

The conduit straight vane mixer 2200 provides relatively high swirlvelocities even at lower blade angles for each of the conduit straightvanes 2202, thereby providing enhanced mixing of reductant with a lowerpressure drop. Another benefit of the high swirl velocities provided bythe conduit straight vanes 2202 and the combined conduit straight vaneis that high swirl velocities mitigate accumulation of depositsdownstream of the conduit straight vane mixer 2200 (e.g., along theVenturi body 302, along the shroud 1308, etc.).

Each of the conduit straight vanes 2202 and the combined conduitstraight vane is defined by a streamwise angle ∝_(sa) relative to anaxis upon which the conduit straight vane hub 2206 is centered. Invarious embodiments, the streamwise angle ∝_(sa) is between thirtydegrees and ninety degrees, inclusive. The streamwise angle ∝_(sa), foreach of the conduit straight vanes 2202 and the combined conduitstraight vanes may be selected such that the first flow device 206 istailored for a target application.

The streamwise angle ∝_(sa) and the streamwise extension distance E_(sw)may be different for each of the conduit straight vanes 2202 and/or thecombined conduit straight vanes. Selection of streamwise angle ∝_(sa)and streamwise extension distance E_(sw) for each of the conduitstraight vanes 2202 and/or the combined conduit straight vanes may bemade so as to create asymmetric swirl of the exhaust gases, to directflow of the exhaust gases (e.g., towards a target location in the vaneswirl mixer 200, etc.), to more uniformly distribute reductant withinthe exhaust gases, and/or to reduce deposits within the first flowdevice 206 (e.g., on the Venturi body 302, etc.) and/or the vane swirlmixer 200.

The conduit straight vanes 2202 and/or the combined conduit straightvanes may be constructed using casting (e.g., investment casting, lostfoam casting, sand casting, etc.) and/or 3D printing. For example, theconduit straight vane mixer 2200 may be printed using a 3D printer byusing a file which specifies the number of the conduit straight vanes2202, the number of the combined conduit straight vanes, the streamlineangle ∝_(sa) for each of the conduit straight vanes 2202 and combinedconduit straight vanes, and the streamwise extension E_(sw) for each ofthe conduit straight vanes 2202 and combined conduit straight vanes.

FIG. 8 illustrates a curved vane mixer 2300 according to an exampleembodiment. It is understood that the curved vane mixer 2300 as shownand described with reference to FIG. 9 may be included in any of theembodiments of the vane swirl mixer 200 discussed herein.

In various embodiments, the curved vane mixer 2300 is utilized in thefirst flow device 206 in place of the upstream mixer 1106 or in place ofthe downstream mixer 309.

The curved vane mixer 2300 includes a plurality of curved vanes 2302 anda combined curved vane 2304. In some embodiments, the curved vane mixer2300 includes two, three, four, five, six, seven, eight, or more of thecurved vanes 2302. In some embodiments, the curved vane mixer 2300includes one, two, three or more of the combined curved vanes 2304. Inother embodiments, the curved vane mixer 2300 does not include thecombined curved vane 2304. In an example embodiment, the curved vanemixer 2300 includes three of the curved vanes 2302 and one combinedcurved vane 2304.

Each of the curved vanes 2302 and the combined curved vane 2304 isattached to a curved vane hub 2306 that is offset from the mixer centeraxis by HU_(offset), as detailed above. The curved vanes 2302 and/or thecombined curved vane 2304 may be arranged symmetrically orasymmetrically about the curved vane hub 2306. Like the conduit straightvanes 2202, each of the curved vanes 2302 and the combined curved vane2304 may overlap. Each of the curved vanes 2302 and the combined curvedvane 2304 extend over an adjacent curved vane 2302 or combined curvedvane 2304 the extension distance E_(sw) described herein.

The curved vanes 2302 and the combined curved vane 2304 have a curved oraerodynamic shape which reduces pressure drop of the exhaust gases andfacilitates more even distribution of the flow downstream of the curvedvane mixer 2300, such as along a center axis of the curved vane mixer2300.

Each of the curved vanes 2302 is defined by a curved vane angle α_(CV)relative to a curved vane hub center axis of the curved vane hub 2306.Similarly, the combined curved vane 2304 may be defined by the curvedvane angle α_(CV) relative to a curved vane hub center axis of thecurved vane hub 2306. Due to the curved nature of the curved vanes 2302and the combined curved vane 2304, the curved vane angle α_(CV) isvariable. The curved vane angle for each of the curved vanes 2302 andcombined curved vanes 2304 may be different from the curved vane angleα_(CV) for the others of the curved vanes 2302 and the others of thecombined curved vanes 2304.

The curved vanes 2302 and/or the combined curved vane 2304 may beconstructed using casting and/or 3D printing. For example, the curvedvane mixer 2300 may be printed using a 3D printer by using a file whichspecifies the number of the curved vanes 2302, the number of thecombined curved vanes 2304, and the curved vane angle α_(CV) for each ofthe curved vanes 2302 and the combined curved vanes 2304. In variousembodiments, the curved vanes 2302 and/or the combined curved vane 2304can be design to keep a tangential angle constant at each point alongthe curved vane 2302 or combined curved vane 2304, or to minimize anaerodynamic drag force on each curved vane 2302 or combined curved vane2304. In one embodiment, 3D printed or cast curved vanes 2303 may beinserted into the Venturi body 302 and welded to the first supportflange 304.

FIGS. 9 and 10 illustrate a shrouded vane mixer 3100 according to anexample embodiment. It is understood that the shrouded vane mixer 3100as shown and described with reference to FIGS. 9 and 10 may be includedin any of the embodiments of the multi-stage mixer 200 discussed herein.

FIG. 10 is a cross-sectional view of the shrouded vane mixer 3100. Invarious embodiments, the shrouded vane mixer 3100 is utilized in thefirst flow device 206 in place of the upstream mixer 1106 or in place ofthe downstream mixer 309.

The shrouded vane mixer 3100 includes a plurality of shrouded vanes 3102and a combined shrouded vane 3104. In some embodiments, the shroudedvane mixer 3100 includes two, three, four, five, six, seven, eight, ormore of the shrouded vanes 3102. In some embodiments, the shrouded vanemixer 3100 includes one, two, three or more of the combined shroudedvanes 3104. In other embodiments, the shrouded vane mixer 3100 does notinclude the combined shrouded vane 3104. In an example embodiment, theshrouded vane mixer 3100 includes three of the shrouded vanes 3102 andone combined shrouded vane 3104.

Each of the shrouded vanes 3102 and the combined shrouded vane 3104 isattached to a shrouded vane hub 3106 that is offset from the center axisof the vane swirl mixer by HU_(offset), as detailed above. The shroudedvanes 3102 and/or the combined shrouded vane 3104 may be arrangedsymmetrically or asymmetrically about the shrouded vane central hub3106. Like the conduit straight vanes 2202, each of the shrouded vanes3102 and the combined shrouded vane 3104 may overlap.

The shrouded vane mixer 3100 includes a recess 2908. The recess 2908 isconfigured to fit around the exhaust gas guide aperture 306 when theshrouded vane mixer 3100 is installed in the vane swirl mixer 200.

The shrouded vane mixer 3100 combines the functions of a mixer (e.g.,the upstream mixer 1106, the downstream mixer 309, etc.) with thefunctions of a shroud (e.g., the shroud 1308, etc.) in a singlecomponent. In this way, the shrouded vane mixer 3100 may reduce the cost(e.g., manufacturing cost, etc.) and manufacturing complexity of thevane swirl mixer 200. Additionally, combining the mixer and the shroudin a single component, the shrouded vane mixer 3100, reducesmanufacturing tolerances on vane angles of the shrouded vanes 3102,thereby reducing variability between different shrouded vane mixers3100. The thickness of each of the shrouded vanes 3102 may be constantor variable throughout the shrouded vane 3102, such as vertically alongthe shrouded vane 3102 or horizontally along the shrouded vane 3102. Invarious embodiments, the shrouded vane 3102 has a thickness of between1.5 mm and 6 mm, inclusive. Similarly, in various embodiments, the edgesof each of the shrouded vanes 3102 have a radius of between 0.5 mm and 3mm, inclusive. This radius may reduce flow separation of the exhaustgases, mitigate accumulation of reductant deposits, and reduce stressconcentrations on the shrouded vanes 3102 and/or the shroud 1318.

FIG. 11 illustrates a comparison, determined via computational fluiddynamics (CFD) calculations, of the normalized pressure drop, the flowuniformity index and the reductant uniformity index of the vane swirlmixer according to the embodiment shown in FIGS. 2 to 4 and describedabove and a previous design of a vane swirl mixer as detailed in WO2018/226626 A1, wherein the mixer lengths for both variants are thesame. As can be seen the improved design with angle blades that differin length and/or angle leads to an improvement of the uniformity of theexhaust flow and the reductant at the catalyst inlet downstream of themixer, as well as a reduction of the pressure drop at the exhaust gasguide aperture. A reduced pressure drop correlates with a reducedexhaust swirl velocity which is beneficial to reduce the possibility oferosion of the catalyst. It is further possible to include additionalflow devices downstream of the vane swirl mixer and upstream of theflow-through or wall-flow catalyst to further improve the flowdistribution. These flow devices may be perforated plates or similardevices with predefined open areas.

IV. Construction of Example Embodiments

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of what may beclaimed but rather as descriptions of features specific to particularimplementations. Certain features described in this specification in thecontext of separate implementations can also be implemented incombination in a single implementation. Conversely, various featuresdescribed in the context of a single implementation can also beimplemented in multiple implementations separately or in any suitablesubcombination. Moreover, although features may be described as actingin certain combinations and even initially claimed as such, one or morefeatures from a claimed combination can, in some cases, be excised fromthe combination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

As utilized herein, the terms “substantially,” “approximately,” andsimilar terms are intended to have a broad meaning in harmony with thecommon and accepted usage by those of ordinary skill in the art to whichthe subject matter of this disclosure pertains. It should be understoodby those of skill in the art who review this disclosure that these termsare intended to allow a description of certain features described andclaimed without restricting the scope of these features to the precisenumerical ranges provided. Accordingly, these terms should beinterpreted as indicating that insubstantial or inconsequentialmodifications or alterations of the subject matter described and claimedare considered to be within the scope of the invention as recited in theappended claims.

The terms “coupled,” “connected,” and the like, as used herein, mean thejoining of two components directly or indirectly to one another. Suchjoining may be stationary (e.g., permanent) or moveable (e.g., removableor releasable). Such joining may be achieved with the two components orthe two components and any additional intermediate components beingintegrally formed as a single unitary body with one another, with thetwo components, or with the two components and any additionalintermediate components being attached to one another.

The terms “fluidly coupled,” “in fluid communication,” and the like, asused herein, mean the two components or objects have a pathway formedbetween the two components or objects in which a fluid, such as exhaust,water, air, gaseous reductant, gaseous ammonia, etc., may flow, eitherwith or without intervening components or objects. Examples of fluidcouplings or configurations for enabling fluid communication may includepiping, channels, or any other suitable components for enabling the flowof a fluid from one component or object to another. As described herein,“preventing” should be interpreted as potentially allowing for deminimus circumvention (e.g., less than 1) of the exhaust gases.

It should be understood that some features may not be necessary, andimplementations lacking the various features may be contemplated aswithin the scope of the application, the scope being defined by theclaims that follow. When the language “a portion” is used, the item caninclude a portion and/or the entire item unless specifically stated tothe contrary.

The invention claimed is:
 1. A vane swirl mixer for an exhaust gasaftertreatment system, the vane swirl mixer comprising: a vane swirlmixer inlet configured to receive exhaust gas; a vane swirl mixer outletconfigured to provide the exhaust gas from the vane swirl mixer; and afirst flow device configured to receive the exhaust gas from the vaneswirl mixer inlet, receive a reductant, and facilitate mixing of theexhaust gas and the reductant within the first flow device, the firstflow device comprising: a Venturi body centered on a body center axis,the Venturi body comprising: a body inlet configured to receive theexhaust gas from the vane swirl mixer inlet; and a body outletconfigured to provide the exhaust gas to the vane swirl mixer outlet; afirst upstream vane positioned within the Venturi body proximate thebody inlet and coupled to an upstream vane hub that is centered on anupstream vane hub axis, the first upstream vane configured to facilitateswirling of the exhaust gas within the Venturi body; and a firstdownstream vane positioned within the Venturi body proximate the bodyoutlet and coupled to a downstream vane hub that is centered on adownstream vane hub axis, the first downstream vane configured tofacilitate swirling of the exhaust gas downstream of the Body outlet;wherein at least one of: the upstream vane hub axis is radially offsetfrom the body center axis by an offset distance; or the downstream vanehub axis is radially offset from the body center axis by an offsetdistance.
 2. The vane swirl mixer of claim 1, wherein: the Venturi bodyis defined by a Venturi diameter; the vane swirl mixer is defined by aninner diameter; and the Venturi diameter is between 25% of the innerdiameter and 90% of the inner diameter, inclusive.
 3. The vane swirlmixer of claim 2, wherein the offset distance is less than or equal to25% of the Venturi diameter.
 4. The vane swirl mixer of claim 2,wherein: the body outlet is defined by an outlet diameter; and theoutlet diameter is between 70% of the Venturi diameter and 100% of theVenturi diameter, inclusive.
 5. The vane swirl mixer of claim 1, furthercomprising a second upstream vane positioned within the Venturi bodyproximate the body inlet and coupled to the upstream vane hub, thesecond upstream vane configured to facilitate swirling of the exhaustgas within the Venturi body, the second upstream vane comprising asecond upstream vane edge extending from the upstream vane hub towardsthe Venturi body, the second upstream vane edge defined by a secondupstream vane edge length; wherein the first upstream vane and thesecond upstream vane cooperate to define an upstream vane aperture, theupstream vane aperture configured to facilitate passage of the exhaustgas from the body inlet to the first downstream vane; wherein the firstupstream vane comprises a first upstream vane edge extending from theupstream vane hub towards the Venturi body, the first upstream vane edgedefined by a first upstream vane edge length that is different from thesecond upstream vane edge length.
 6. The vane swirl mixer of claim 1,further comprising a second upstream vane positioned within the Venturibody proximate the body inlet and coupled to the upstream vane hub, thesecond upstream vane configured to facilitate swirling of the exhaustgas within the Venturi body; wherein the first upstream vane and thesecond upstream vane cooperate to define an upstream vane aperture, theupstream vane aperture configured to facilitate passage of the exhaustgas from the body inlet to the first downstream vane; wherein theupstream vane hub is disposed along an upstream vane hub plane; whereinthe upstream vane hub axis is orthogonal to the upstream vane hub plane;wherein the first upstream vane comprises a first upstream vane edgeextending from the upstream vane hub towards the Venturi body, the firstupstream vane edge defined by a first upstream vane edge angle relativeto the upstream vane hub plane; and wherein the second upstream vanecomprises a second upstream vane edge extending from the upstream vanehub towards the Venturi body, the second upstream vane edge defined by asecond upstream vane edge angle relative to the upstream vane hub plane,the second upstream vane edge angle different from the first upstreamvane edge angle.
 7. The vane swirl mixer of claim 1, further comprisinga second downstream vane positioned within the Venturi body proximatethe body outlet and coupled to the downstream vane hub, the seconddownstream vane configured to facilitate swirling of the exhaust gasdownstream of the Body outlet, the second downstream vane comprising asecond downstream vane edge extending from the downstream vane hubtowards the Venturi body, the second downstream vane edge defined by asecond downstream vane edge length; wherein the first downstream vaneand the second downstream vane cooperate to define a downstream vaneaperture, the downstream vane aperture configured to facilitate passageof the exhaust gas from the first upstream vane to the body outlet;wherein the first downstream vane comprises a first downstream vane edgeextending from the downstream vane hub towards the Venturi body, thefirst downstream vane edge defined by a first downstream vane edgelength that is different from the second downstream vane edge length. 8.The vane swirl mixer of claim 1, further comprising a second downstreamvane positioned within the Venturi body proximate the body outlet andcoupled to the downstream vane hub, the second downstream vaneconfigured to facilitate swirling of the exhaust gas downstream of theBody outlet; wherein the first downstream vane and the second downstreamvane cooperate to define a downstream vane aperture, the downstream vaneaperture configured to facilitate passage of the exhaust gas from thefirst upstream vane to the body outlet; wherein the downstream vane hubis disposed along a downstream vane hub plane; wherein the downstreamvane hub axis is orthogonal to the downstream vane hub plane; whereinthe first downstream vane comprises a first downstream vane edgeextending from the downstream vane hub towards the Venturi body, thefirst downstream vane edge defined by a first downstream vane edge anglerelative to the downstream vane hub plane; and wherein the seconddownstream vane comprises a second downstream vane edge extending fromthe downstream vane hub towards the Venturi body, the second downstreamvane edge defined by a second downstream vane edge angle relative to thedownstream vane hub plane, the second downstream vane edge angledifferent from the first downstream vane edge angle.
 9. A vane swirlmixer for an exhaust gas aftertreatment system, the vane swirl mixercomprising: a vane swirl mixer inlet configured to receive exhaust gas;a vane swirl mixer outlet configured to provide the exhaust gas from thevane swirl mixer; and a first flow device configured to receive theexhaust gas from the vane swirl mixer inlet and facilitate mixing of theexhaust gas and a reductant within the first flow device, the first flowdevice comprising: a Venturi body centered on a body center axis, theVenturi body comprising: a body inlet configured to receive the exhaustgas from the vane swirl mixer inlet; and a body outlet configured toprovide the exhaust gas to the vane swirl mixer outlet; a first upstreamvane positioned within the Venturi body proximate the body inlet andcoupled to an upstream vane hub that is centered on an upstream vane hubaxis and radially offset from the body center axis by an offsetdistance, the first upstream vane configured to facilitate swirling ofthe exhaust gas within the Venturi body.
 10. The vane swirl mixer ofclaim 9, further comprising a second upstream vane positioned within theVenturi body proximate the body inlet and coupled to the upstream vanehub, the second upstream vane configured to facilitate swirling of theexhaust gas within the Venturi body, the second upstream vane comprisinga second upstream vane edge extending from the upstream vane hub towardsthe Venturi body, the second upstream vane edge defined by a secondupstream vane edge length; wherein the first upstream vane and thesecond upstream vane cooperate to define an upstream vane aperture, theupstream vane aperture configured to facilitate passage of the exhaustgas from the body inlet to the body outlet; wherein the first upstreamvane comprises a first upstream vane edge extending from the upstreamvane hub towards the Venturi body, the first upstream vane edge definedby a first upstream vane edge length that is different from the secondupstream vane edge length.
 11. The vane swirl mixer of claim 9, furthercomprising a second upstream vane positioned within the Venturi bodyproximate the body inlet and coupled to the upstream vane hub, thesecond upstream vane configured to facilitate swirling of the exhaustgas within the Venturi body; wherein the first upstream vane and thesecond upstream vane cooperate to define an upstream vane aperture, theupstream vane aperture configured to facilitate passage of the exhaustgas from the body inlet to the body outlet; wherein the upstream vanehub is disposed along an upstream vane hub plane; wherein the upstreamvane hub axis is orthogonal to the upstream vane hub plane; wherein thefirst upstream vane comprises a first upstream vane edge extending fromthe upstream vane hub towards the Venturi body, the first upstream vaneedge defined by a first upstream vane edge angle relative to theupstream vane hub plane; and wherein the second upstream vane comprisesa second upstream vane edge extending from the upstream vane hub towardsthe Venturi body, the second upstream vane edge defined by a secondupstream vane edge angle relative to the upstream vane hub plane, thesecond upstream vane edge angle different from the first upstream vaneedge angle.
 12. The vane swirl mixer of claim 9, wherein: the Venturibody is defined by a Venturi diameter; the body outlet is defined by anoutlet diameter; and the outlet diameter is between 70% of the Venturidiameter and 100% of the Venturi diameter, inclusive.
 13. The vane swirlmixer of claim 12, wherein the offset distance is less than or equal to25% of the Venturi diameter.
 14. The vane swirl mixer of claim 12,wherein: the vane swirl mixer is defined by an inner diameter; and theVenturi diameter is between 25% of the inner diameter and 90% of theinner diameter, inclusive.
 15. A vane swirl mixer for an exhaust gasaftertreatment system, the vane swirl mixer comprising: a vane swirlmixer inlet configured to receive exhaust gas; a vane swirl mixer outletconfigured to provide the exhaust gas from the vane swirl mixer; and afirst flow device configured to receive the exhaust gas from the vaneswirl mixer inlet, receive a reductant, and facilitate mixing of theexhaust gas and the reductant within the first flow device, the firstflow device comprising: a Venturi body centered on a body center axis,the Venturi body comprising: a body inlet configured to receive theexhaust gas from the vane swirl mixer inlet; and a body outletconfigured to provide the exhaust gas to the vane swirl mixer outlet;and a first downstream vane positioned within the Venturi body proximatethe body outlet and coupled to a downstream vane hub that is centered ona downstream vane hub axis and is radially offset from the body centeraxis by an offset distance, the first downstream vane configured tofacilitate swirling of the exhaust gas downstream of the Body outlet.16. The vane swirl mixer of claim 15, wherein: the Venturi body isdefined by a Venturi diameter; and the offset distance is less than orequal to 25% of the Venturi diameter.
 17. The vane swirl mixer of claim16, wherein: the vane swirl mixer is defined by an inner diameter; andthe Venturi diameter is between 25% of the inner diameter and 90% of theinner diameter, inclusive.
 18. The vane swirl mixer of claim 17,wherein: the body outlet is defined by an outlet diameter; and theoutlet diameter is between 70% of the Venturi diameter and 100% of theVenturi diameter, inclusive.
 19. The vane swirl mixer of claim 15,further comprising a second downstream vane positioned within theVenturi body proximate the body outlet and coupled to the downstreamvane hub, the second downstream vane configured to facilitate swirlingof the exhaust gas downstream of the Body outlet, the second downstreamvane comprising a second downstream vane edge extending from thedownstream vane hub towards the Venturi body, the second downstream vaneedge defined by a second downstream vane edge length; wherein the firstdownstream vane and the second downstream vane cooperate to define adownstream vane aperture, the downstream vane aperture configured tofacilitate passage of the exhaust gas from the body inlet to the bodyoutlet; wherein the first downstream vane comprises a first downstreamvane edge extending from the downstream vane hub towards the Venturibody, the first downstream vane edge defined by a first downstream vaneedge length that is different from the second downstream vane edgelength.
 20. The vane swirl mixer of claim 15, further comprising asecond downstream vane positioned within the Venturi body proximate thebody outlet and coupled to the downstream vane hub, the seconddownstream vane configured to facilitate swirling of the exhaust gasdownstream of the Body outlet; wherein the first downstream vane and thesecond downstream vane cooperate to define a downstream vane aperture,the downstream vane aperture configured to facilitate passage of theexhaust gas from the body inlet to the body outlet; wherein thedownstream vane hub is disposed along a downstream vane hub plane;wherein the downstream vane hub axis is orthogonal to the downstreamvane hub plane; wherein the first downstream vane comprises a firstdownstream vane edge extending from the downstream vane hub towards theVenturi body, the first downstream vane edge defined by a firstdownstream vane edge angle relative to the downstream vane hub plane;and wherein the second downstream vane comprises a second downstreamvane edge extending from the downstream vane hub towards the Venturibody, the second downstream vane edge defined by a second downstreamvane edge angle relative to the downstream vane hub plane, the seconddownstream vane edge angle different from the first downstream vane edgeangle.